829 lines
22 KiB
C++
829 lines
22 KiB
C++
//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
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//
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// Purpose:
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//
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// $NoKeywords: $
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//
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//=============================================================================//
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// nav_pathfind.h
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// Path-finding mechanisms using the Navigation Mesh
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// Author: Michael S. Booth (mike@turtlerockstudios.com), January 2003
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#ifndef _NAV_PATHFIND_H_
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#define _NAV_PATHFIND_H_
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#include "tier0/vprof.h"
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#include "mathlib/ssemath.h"
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#include "nav_area.h"
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extern int g_DebugPathfindCounter;
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//-------------------------------------------------------------------------------------------------------------------
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/**
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* Used when building a path to determine the kind of path to build
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*/
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enum RouteType
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{
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DEFAULT_ROUTE,
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FASTEST_ROUTE,
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SAFEST_ROUTE,
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RETREAT_ROUTE,
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};
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//--------------------------------------------------------------------------------------------------------------
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/**
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* Functor used with NavAreaBuildPath()
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*/
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class ShortestPathCost
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{
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public:
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float operator() ( CNavArea *area, CNavArea *fromArea, const CNavLadder *ladder, const CFuncElevator *elevator, float length )
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{
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if ( fromArea == NULL )
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{
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// first area in path, no cost
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return 0.0f;
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}
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else
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{
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// compute distance traveled along path so far
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float dist;
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if ( ladder )
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{
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dist = ladder->m_length;
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}
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else if ( length > 0.0 )
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{
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dist = length;
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}
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else
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{
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dist = ( area->GetCenter() - fromArea->GetCenter() ).Length();
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}
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float cost = dist + fromArea->GetCostSoFar();
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// if this is a "crouch" area, add penalty
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if ( area->GetAttributes() & NAV_MESH_CROUCH )
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{
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const float crouchPenalty = 20.0f; // 10
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cost += crouchPenalty * dist;
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}
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// if this is a "jump" area, add penalty
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if ( area->GetAttributes() & NAV_MESH_JUMP )
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{
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const float jumpPenalty = 5.0f;
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cost += jumpPenalty * dist;
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}
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return cost;
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}
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}
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};
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//--------------------------------------------------------------------------------------------------------------
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/**
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* Find path from startArea to goalArea via an A* search, using supplied cost heuristic.
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* If cost functor returns -1 for an area, that area is considered a dead end.
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* This doesn't actually build a path, but the path is defined by following parent
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* pointers back from goalArea to startArea.
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* If 'closestArea' is non-NULL, the closest area to the goal is returned (useful if the path fails).
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* If 'goalArea' is NULL, will compute a path as close as possible to 'goalPos'.
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* If 'goalPos' is NULL, will use the center of 'goalArea' as the goal position.
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* If 'maxPathLength' is nonzero, path building will stop when this length is reached.
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* Returns true if a path exists.
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*/
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#define IGNORE_NAV_BLOCKERS true
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template< typename CostFunctor >
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bool NavAreaBuildPath( CNavArea *startArea, CNavArea *goalArea, const Vector *goalPos, CostFunctor &costFunc, CNavArea **closestArea = NULL, float maxPathLength = 0.0f, int teamID = TEAM_ANY, bool ignoreNavBlockers = false )
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{
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VPROF_BUDGET( "NavAreaBuildPath", "NextBotSpiky" );
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if ( closestArea )
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{
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*closestArea = startArea;
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}
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bool isDebug = ( g_DebugPathfindCounter-- > 0 );
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if (startArea == NULL)
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return false;
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if (goalArea != NULL && goalArea->IsBlocked( teamID, ignoreNavBlockers ))
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goalArea = NULL;
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if (goalArea == NULL && goalPos == NULL)
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return false;
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startArea->SetParent( NULL );
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// if we are already in the goal area, build trivial path
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if (startArea == goalArea)
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{
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goalArea->SetParent( NULL );
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return true;
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}
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// determine actual goal position
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Vector actualGoalPos = (goalPos) ? *goalPos : goalArea->GetCenter();
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// start search
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CNavArea::ClearSearchLists();
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// compute estimate of path length
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/// @todo Cost might work as "manhattan distance"
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startArea->SetTotalCost( (startArea->GetCenter() - actualGoalPos).Length() );
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float initCost = costFunc( startArea, NULL, NULL, NULL, -1.0f );
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if (initCost < 0.0f)
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return false;
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startArea->SetCostSoFar( initCost );
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startArea->SetPathLengthSoFar( 0.0 );
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startArea->AddToOpenList();
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// keep track of the area we visit that is closest to the goal
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if (closestArea)
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*closestArea = startArea;
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float closestAreaDist = startArea->GetTotalCost();
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// do A* search
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while( !CNavArea::IsOpenListEmpty() )
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{
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// get next area to check
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CNavArea *area = CNavArea::PopOpenList();
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if ( isDebug )
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{
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area->DrawFilled( 0, 255, 0, 128, 30.0f );
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}
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// don't consider blocked areas
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if ( area->IsBlocked( teamID, ignoreNavBlockers ) )
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continue;
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// check if we have found the goal area or position
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if (area == goalArea || (goalArea == NULL && goalPos && area->Contains( *goalPos )))
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{
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if (closestArea)
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{
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*closestArea = area;
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}
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return true;
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}
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// search adjacent areas
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enum SearchType
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{
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SEARCH_FLOOR, SEARCH_LADDERS, SEARCH_ELEVATORS
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};
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SearchType searchWhere = SEARCH_FLOOR;
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int searchIndex = 0;
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int dir = NORTH;
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const NavConnectVector *floorList = area->GetAdjacentAreas( NORTH );
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bool ladderUp = true;
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const NavLadderConnectVector *ladderList = NULL;
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enum { AHEAD = 0, LEFT, RIGHT, BEHIND, NUM_TOP_DIRECTIONS };
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int ladderTopDir = AHEAD;
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bool bHaveMaxPathLength = ( maxPathLength > 0.0f );
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float length = -1;
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while( true )
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{
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CNavArea *newArea = NULL;
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NavTraverseType how;
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const CNavLadder *ladder = NULL;
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const CFuncElevator *elevator = NULL;
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//
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// Get next adjacent area - either on floor or via ladder
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//
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if ( searchWhere == SEARCH_FLOOR )
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{
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// if exhausted adjacent connections in current direction, begin checking next direction
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if ( searchIndex >= floorList->Count() )
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{
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++dir;
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if ( dir == NUM_DIRECTIONS )
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{
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// checked all directions on floor - check ladders next
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searchWhere = SEARCH_LADDERS;
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ladderList = area->GetLadders( CNavLadder::LADDER_UP );
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searchIndex = 0;
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ladderTopDir = AHEAD;
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}
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else
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{
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// start next direction
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floorList = area->GetAdjacentAreas( (NavDirType)dir );
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searchIndex = 0;
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}
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continue;
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}
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const NavConnect &floorConnect = floorList->Element( searchIndex );
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newArea = floorConnect.area;
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length = floorConnect.length;
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how = (NavTraverseType)dir;
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++searchIndex;
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if ( IsX360() && searchIndex < floorList->Count() )
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{
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PREFETCH360( floorList->Element( searchIndex ).area, 0 );
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}
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}
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else if ( searchWhere == SEARCH_LADDERS )
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{
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if ( searchIndex >= ladderList->Count() )
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{
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if ( !ladderUp )
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{
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// checked both ladder directions - check elevators next
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searchWhere = SEARCH_ELEVATORS;
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searchIndex = 0;
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ladder = NULL;
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}
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else
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{
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// check down ladders
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ladderUp = false;
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ladderList = area->GetLadders( CNavLadder::LADDER_DOWN );
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searchIndex = 0;
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}
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continue;
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}
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if ( ladderUp )
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{
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ladder = ladderList->Element( searchIndex ).ladder;
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// do not use BEHIND connection, as its very hard to get to when going up a ladder
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if ( ladderTopDir == AHEAD )
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{
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newArea = ladder->m_topForwardArea;
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}
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else if ( ladderTopDir == LEFT )
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{
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newArea = ladder->m_topLeftArea;
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}
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else if ( ladderTopDir == RIGHT )
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{
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newArea = ladder->m_topRightArea;
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}
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else
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{
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++searchIndex;
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ladderTopDir = AHEAD;
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continue;
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}
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how = GO_LADDER_UP;
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++ladderTopDir;
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}
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else
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{
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newArea = ladderList->Element( searchIndex ).ladder->m_bottomArea;
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how = GO_LADDER_DOWN;
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ladder = ladderList->Element(searchIndex).ladder;
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++searchIndex;
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}
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if ( newArea == NULL )
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continue;
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length = -1.0f;
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}
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else // if ( searchWhere == SEARCH_ELEVATORS )
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{
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const NavConnectVector &elevatorAreas = area->GetElevatorAreas();
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elevator = area->GetElevator();
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if ( elevator == NULL || searchIndex >= elevatorAreas.Count() )
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{
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// done searching connected areas
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elevator = NULL;
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break;
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}
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newArea = elevatorAreas[ searchIndex++ ].area;
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if ( newArea->GetCenter().z > area->GetCenter().z )
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{
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how = GO_ELEVATOR_UP;
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}
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else
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{
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how = GO_ELEVATOR_DOWN;
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}
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length = -1.0f;
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}
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// don't backtrack
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if ( newArea == area )
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continue;
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// don't consider blocked areas
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if ( newArea->IsBlocked( teamID, ignoreNavBlockers ) )
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continue;
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float newCostSoFar = costFunc( newArea, area, ladder, elevator, length );
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// check if cost functor says this area is a dead-end
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if ( newCostSoFar < 0.0f )
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continue;
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// stop if path length limit reached
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if ( bHaveMaxPathLength )
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{
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// keep track of path length so far
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float deltaLength = ( newArea->GetCenter() - area->GetCenter() ).Length();
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float newLengthSoFar = area->GetPathLengthSoFar() + deltaLength;
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if ( newLengthSoFar > maxPathLength )
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continue;
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newArea->SetPathLengthSoFar( newLengthSoFar );
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}
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if ( ( newArea->IsOpen() || newArea->IsClosed() ) && newArea->GetCostSoFar() <= newCostSoFar )
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{
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// this is a worse path - skip it
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continue;
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}
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else
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{
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// compute estimate of distance left to go
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float distSq = ( newArea->GetCenter() - actualGoalPos ).LengthSqr();
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float newCostRemaining = ( distSq > 0.0 ) ? FastSqrt( distSq ) : 0.0 ;
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// track closest area to goal in case path fails
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if ( closestArea && newCostRemaining < closestAreaDist )
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{
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*closestArea = newArea;
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closestAreaDist = newCostRemaining;
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}
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newArea->SetCostSoFar( newCostSoFar );
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newArea->SetTotalCost( newCostSoFar + newCostRemaining );
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if ( newArea->IsClosed() )
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{
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newArea->RemoveFromClosedList();
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}
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if ( newArea->IsOpen() )
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{
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// area already on open list, update the list order to keep costs sorted
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newArea->UpdateOnOpenList();
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}
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else
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{
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newArea->AddToOpenList();
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}
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newArea->SetParent( area, how );
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}
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}
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// we have searched this area
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area->AddToClosedList();
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}
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return false;
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}
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//--------------------------------------------------------------------------------------------------------------
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/**
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* Compute distance between two areas. Return -1 if can't reach 'endArea' from 'startArea'.
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*/
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template< typename CostFunctor >
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float NavAreaTravelDistance( CNavArea *startArea, CNavArea *endArea, CostFunctor &costFunc, float maxPathLength = 0.0f )
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{
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if (startArea == NULL)
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return -1.0f;
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if (endArea == NULL)
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return -1.0f;
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if (startArea == endArea)
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return 0.0f;
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// compute path between areas using given cost heuristic
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if (NavAreaBuildPath( startArea, endArea, NULL, costFunc, NULL, maxPathLength ) == false)
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return -1.0f;
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// compute distance along path
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float distance = 0.0f;
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for( CNavArea *area = endArea; area->GetParent(); area = area->GetParent() )
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{
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distance += (area->GetCenter() - area->GetParent()->GetCenter()).Length();
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}
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return distance;
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}
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//--------------------------------------------------------------------------------------------------------------
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/**
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* Do a breadth-first search, invoking functor on each area.
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* If functor returns 'true', continue searching from this area.
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* If functor returns 'false', the area's adjacent areas are not explored (dead end).
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* If 'maxRange' is 0 or less, no range check is done (all areas will be examined).
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*
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* NOTE: Returns all areas that overlap range, even partially
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*
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* @todo Use ladder connections
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*/
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// helper function
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inline void AddAreaToOpenList( CNavArea *area, CNavArea *parent, const Vector &startPos, float maxRange )
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{
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if (area == NULL)
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return;
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if (!area->IsMarked())
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{
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area->Mark();
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area->SetTotalCost( 0.0f );
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area->SetParent( parent );
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if (maxRange > 0.0f)
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{
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// make sure this area overlaps range
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Vector closePos;
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area->GetClosestPointOnArea( startPos, &closePos );
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if ((closePos - startPos).AsVector2D().IsLengthLessThan( maxRange ))
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{
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// compute approximate distance along path to limit travel range, too
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float distAlong = parent->GetCostSoFar();
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distAlong += (area->GetCenter() - parent->GetCenter()).Length();
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area->SetCostSoFar( distAlong );
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// allow for some fudge due to large size areas
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if (distAlong <= 1.5f * maxRange)
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area->AddToOpenList();
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}
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}
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else
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{
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// infinite range
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area->AddToOpenList();
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}
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}
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}
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/****************************************************************
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* DEPRECATED: Use filter-based SearchSurroundingAreas below
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****************************************************************/
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#define INCLUDE_INCOMING_CONNECTIONS 0x1
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#define INCLUDE_BLOCKED_AREAS 0x2
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#define EXCLUDE_OUTGOING_CONNECTIONS 0x4
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#define EXCLUDE_ELEVATORS 0x8
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template < typename Functor >
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void SearchSurroundingAreas( CNavArea *startArea, const Vector &startPos, Functor &func, float maxRange = -1.0f, unsigned int options = 0, int teamID = TEAM_ANY )
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{
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if (startArea == NULL)
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return;
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CNavArea::MakeNewMarker();
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CNavArea::ClearSearchLists();
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startArea->AddToOpenList();
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startArea->SetTotalCost( 0.0f );
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startArea->SetCostSoFar( 0.0f );
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startArea->SetParent( NULL );
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startArea->Mark();
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while( !CNavArea::IsOpenListEmpty() )
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{
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// get next area to check
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CNavArea *area = CNavArea::PopOpenList();
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// don't use blocked areas
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if ( area->IsBlocked( teamID ) && !(options & INCLUDE_BLOCKED_AREAS) )
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continue;
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// invoke functor on area
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if (func( area ))
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{
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// explore adjacent floor areas
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for( int dir=0; dir<NUM_DIRECTIONS; ++dir )
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{
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int count = area->GetAdjacentCount( (NavDirType)dir );
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for( int i=0; i<count; ++i )
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{
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CNavArea *adjArea = area->GetAdjacentArea( (NavDirType)dir, i );
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if ( options & EXCLUDE_OUTGOING_CONNECTIONS )
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{
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if ( !adjArea->IsConnected( area, NUM_DIRECTIONS ) )
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{
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continue; // skip this outgoing connection
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}
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}
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AddAreaToOpenList( adjArea, area, startPos, maxRange );
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}
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}
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// potentially include areas that connect TO this area via a one-way link
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if (options & INCLUDE_INCOMING_CONNECTIONS)
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{
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for( int dir=0; dir<NUM_DIRECTIONS; ++dir )
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{
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const NavConnectVector *list = area->GetIncomingConnections( (NavDirType)dir );
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FOR_EACH_VEC( (*list), it )
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{
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NavConnect connect = (*list)[ it ];
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AddAreaToOpenList( connect.area, area, startPos, maxRange );
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}
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}
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}
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// explore adjacent areas connected by ladders
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// check up ladders
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const NavLadderConnectVector *ladderList = area->GetLadders( CNavLadder::LADDER_UP );
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if (ladderList)
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{
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FOR_EACH_VEC( (*ladderList), it )
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{
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const CNavLadder *ladder = (*ladderList)[ it ].ladder;
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// do not use BEHIND connection, as its very hard to get to when going up a ladder
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AddAreaToOpenList( ladder->m_topForwardArea, area, startPos, maxRange );
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|
AddAreaToOpenList( ladder->m_topLeftArea, area, startPos, maxRange );
|
|
AddAreaToOpenList( ladder->m_topRightArea, area, startPos, maxRange );
|
|
}
|
|
}
|
|
|
|
// check down ladders
|
|
ladderList = area->GetLadders( CNavLadder::LADDER_DOWN );
|
|
if (ladderList)
|
|
{
|
|
FOR_EACH_VEC( (*ladderList), it )
|
|
{
|
|
const CNavLadder *ladder = (*ladderList)[ it ].ladder;
|
|
|
|
AddAreaToOpenList( ladder->m_bottomArea, area, startPos, maxRange );
|
|
}
|
|
}
|
|
|
|
if ( (options & EXCLUDE_ELEVATORS) == 0 )
|
|
{
|
|
const NavConnectVector &elevatorList = area->GetElevatorAreas();
|
|
FOR_EACH_VEC( elevatorList, it )
|
|
{
|
|
CNavArea *elevatorArea = elevatorList[ it ].area;
|
|
AddAreaToOpenList( elevatorArea, area, startPos, maxRange );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//--------------------------------------------------------------------------------------------------------------
|
|
/**
|
|
* Derive your own custom search functor from this interface method for use with SearchSurroundingAreas below.
|
|
*/
|
|
class ISearchSurroundingAreasFunctor
|
|
{
|
|
public:
|
|
virtual ~ISearchSurroundingAreasFunctor() { }
|
|
|
|
/**
|
|
* Perform user-defined action on area.
|
|
* Return 'false' to end the search (ie: you found what you were looking for)
|
|
*/
|
|
virtual bool operator() ( CNavArea *area, CNavArea *priorArea, float travelDistanceSoFar ) = 0;
|
|
|
|
// return true if 'adjArea' should be included in the ongoing search
|
|
virtual bool ShouldSearch( CNavArea *adjArea, CNavArea *currentArea, float travelDistanceSoFar )
|
|
{
|
|
return !adjArea->IsBlocked( TEAM_ANY );
|
|
}
|
|
|
|
/**
|
|
* Collect adjacent areas to continue the search by calling 'IncludeInSearch' on each
|
|
*/
|
|
virtual void IterateAdjacentAreas( CNavArea *area, CNavArea *priorArea, float travelDistanceSoFar )
|
|
{
|
|
// search adjacent outgoing connections
|
|
for( int dir=0; dir<NUM_DIRECTIONS; ++dir )
|
|
{
|
|
int count = area->GetAdjacentCount( (NavDirType)dir );
|
|
for( int i=0; i<count; ++i )
|
|
{
|
|
CNavArea *adjArea = area->GetAdjacentArea( (NavDirType)dir, i );
|
|
|
|
if ( ShouldSearch( adjArea, area, travelDistanceSoFar ) )
|
|
{
|
|
IncludeInSearch( adjArea, area );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Invoked after the search has completed
|
|
virtual void PostSearch( void ) { }
|
|
|
|
// consider 'area' in upcoming search steps
|
|
void IncludeInSearch( CNavArea *area, CNavArea *priorArea )
|
|
{
|
|
if ( area == NULL )
|
|
return;
|
|
|
|
if ( !area->IsMarked() )
|
|
{
|
|
area->Mark();
|
|
area->SetTotalCost( 0.0f );
|
|
area->SetParent( priorArea );
|
|
|
|
// compute approximate travel distance from start area of search
|
|
if ( priorArea )
|
|
{
|
|
float distAlong = priorArea->GetCostSoFar();
|
|
distAlong += ( area->GetCenter() - priorArea->GetCenter() ).Length();
|
|
area->SetCostSoFar( distAlong );
|
|
}
|
|
else
|
|
{
|
|
area->SetCostSoFar( 0.0f );
|
|
}
|
|
|
|
// adding an area to the open list also marks it
|
|
area->AddToOpenList();
|
|
}
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Do a breadth-first search starting from 'startArea' and continuing outward based on
|
|
* adjacent areas that pass the given filter
|
|
*/
|
|
inline void SearchSurroundingAreas( CNavArea *startArea, ISearchSurroundingAreasFunctor &func )
|
|
{
|
|
if ( startArea )
|
|
{
|
|
CNavArea::MakeNewMarker();
|
|
CNavArea::ClearSearchLists();
|
|
|
|
startArea->AddToOpenList();
|
|
startArea->SetTotalCost( 0.0f );
|
|
startArea->SetCostSoFar( 0.0f );
|
|
startArea->SetParent( NULL );
|
|
startArea->Mark();
|
|
|
|
CUtlVector< CNavArea * > adjVector;
|
|
|
|
while( !CNavArea::IsOpenListEmpty() )
|
|
{
|
|
// get next area to check
|
|
CNavArea *area = CNavArea::PopOpenList();
|
|
|
|
if ( func( area, area->GetParent(), area->GetCostSoFar() ) )
|
|
{
|
|
func.IterateAdjacentAreas( area, area->GetParent(), area->GetCostSoFar() );
|
|
}
|
|
else
|
|
{
|
|
// search aborted
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
func.PostSearch();
|
|
}
|
|
|
|
|
|
//--------------------------------------------------------------------------------------------------------------
|
|
/**
|
|
* Fuctor that returns lowest cost for farthest away areas
|
|
* For use with FindMinimumCostArea()
|
|
*/
|
|
class FarAwayFunctor
|
|
{
|
|
public:
|
|
float operator() ( CNavArea *area, CNavArea *fromArea, const CNavLadder *ladder )
|
|
{
|
|
if (area == fromArea)
|
|
return 9999999.9f;
|
|
|
|
return 1.0f/(fromArea->GetCenter() - area->GetCenter()).Length();
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Fuctor that returns lowest cost for areas farthest from given position
|
|
* For use with FindMinimumCostArea()
|
|
*/
|
|
class FarAwayFromPositionFunctor
|
|
{
|
|
public:
|
|
FarAwayFromPositionFunctor( const Vector &pos ) : m_pos( pos )
|
|
{
|
|
}
|
|
|
|
float operator() ( CNavArea *area, CNavArea *fromArea, const CNavLadder *ladder )
|
|
{
|
|
return 1.0f/(m_pos - area->GetCenter()).Length();
|
|
}
|
|
|
|
private:
|
|
const Vector &m_pos;
|
|
};
|
|
|
|
|
|
/**
|
|
* Pick a low-cost area of "decent" size
|
|
*/
|
|
template< typename CostFunctor >
|
|
CNavArea *FindMinimumCostArea( CNavArea *startArea, CostFunctor &costFunc )
|
|
{
|
|
const float minSize = 150.0f;
|
|
|
|
// collect N low-cost areas of a decent size
|
|
enum { NUM_CHEAP_AREAS = 32 };
|
|
struct
|
|
{
|
|
CNavArea *area;
|
|
float cost;
|
|
}
|
|
cheapAreaSet[ NUM_CHEAP_AREAS ];
|
|
int cheapAreaSetCount = 0;
|
|
|
|
FOR_EACH_VEC( TheNavAreas, iter )
|
|
{
|
|
CNavArea *area = TheNavAreas[iter];
|
|
|
|
// skip the small areas
|
|
if ( area->GetSizeX() < minSize || area->GetSizeY() < minSize)
|
|
continue;
|
|
|
|
// compute cost of this area
|
|
float cost = costFunc( area, startArea, NULL, NULL );
|
|
|
|
if (cheapAreaSetCount < NUM_CHEAP_AREAS)
|
|
{
|
|
cheapAreaSet[ cheapAreaSetCount ].area = area;
|
|
cheapAreaSet[ cheapAreaSetCount++ ].cost = cost;
|
|
}
|
|
else
|
|
{
|
|
// replace most expensive cost if this is cheaper
|
|
int expensive = 0;
|
|
for( int i=1; i<NUM_CHEAP_AREAS; ++i )
|
|
if (cheapAreaSet[i].cost > cheapAreaSet[expensive].cost)
|
|
expensive = i;
|
|
|
|
if (cheapAreaSet[expensive].cost > cost)
|
|
{
|
|
cheapAreaSet[expensive].area = area;
|
|
cheapAreaSet[expensive].cost = cost;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (cheapAreaSetCount)
|
|
{
|
|
// pick one of the areas at random
|
|
return cheapAreaSet[ RandomInt( 0, cheapAreaSetCount-1 ) ].area;
|
|
}
|
|
else
|
|
{
|
|
// degenerate case - no decent sized areas - pick a random area
|
|
int numAreas = TheNavAreas.Count();
|
|
int which = RandomInt( 0, numAreas-1 );
|
|
|
|
FOR_EACH_VEC( TheNavAreas, iter )
|
|
{
|
|
if (which-- == 0)
|
|
return TheNavAreas[iter];
|
|
}
|
|
|
|
}
|
|
return cheapAreaSet[ RandomInt( 0, cheapAreaSetCount-1 ) ].area;
|
|
}
|
|
|
|
|
|
#endif // _NAV_PATHFIND_H_
|